Archived

Avalanche Forecast

Dec 8th, 2014–Dec 9th, 2014

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Banff Yoho Kootenay.

A storm is approaching the forecast region on Tuesday midday. The danger rating will rise.

Weather Forecast

A warm and moist system is approaching the forecast region and is expected to arrive midday on Tuesday. Up to 20cm of snow is expected with strong wind from the west. This will elevate the danger rating late on Tuesday.

Snowpack Summary

Warmer daytime temperatures this weekend are promoting settlement of the upper snowpack and creating more of a slab over the basal facets especially in wind affected areas. The lower half of the snowpack is poorly structured, with facets (Nov 24th) below the recent storm snow, thin crusts (Nov 6th) below this, and then depth hoar near the ground.

Avalanche Summary

No avalanches were observed or reported today.

Confidence

Intensity of incoming weather systems is uncertain on Tuesday

Avalanche Problems

Deep Persistent Slabs

The primary problem in the snowpack is the interface between the recent storm snow and the November 6th and 24th facet/crust interfaces. Owing to the delicate structure of these layers we expect this problem will persist for the foreseeable future.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 2 - 3

Wind Slabs

Mild temperatures and westerly flow will cause wind slabs to develop in exposed areas at tree line and above. Watch for pockets of hard slab near ridge tops and on cross loaded features.

Watch for whumpfing, hollow sounds, and shooting cracks.Be careful with wind loaded pockets while approaching and climbing ice routes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 2